1. Field of the Invention
The present invention relates to an accumulator-dehydrator assembly for use in an air conditioning system.
2. Description of the Prior Art
Vehicle air conditioning systems include a compressor that compresses and superheats refrigerant. The refrigerant exits the compressor and continues first to a condenser and then to an expander. From the expander, the refrigerant enters an evaporator and then returns to the compressor to begin the cycle again. Disposed between the evaporator and compressor is an accumulator-dehydrator assembly which is designed to accomplish several objectives.
The accumulator-dehydrator primarily receives and accumulates the evaporator output which comprises both a liquid component and a vapor component. The accumulator-dehydrator serves as a separator in which fluid collects at the bottom of the canister and vapor at the top.
Typically, an accumulator-dehydrator assembly for use in an air conditioning system includes a canister having an upper portion for containing vaporized refrigerant and a lower portion for containing liquid refrigerant. Mounted to the canister is an inlet to transfer refrigerant from the evaporator to the canister. An outlet is also mounted to the canister to transfer vaporized refrigerant to the compressor from the canister. A delivery tube is positioned within the canister with a first tube end in fluid communication with the upper portion of the canister to receive the vaporized refrigerant and a second tube end is connected to the outlet to deliver vaporized refrigerant to the compressor. The delivery tube extends down from the outlet to near the bottom of the canister and then turns upward and extends to near the top of the canister. An oil pickup is connected to the delivery tube to deliver oil to the delivery tube. The oil is entrained in the vapor refrigerant and delivered to the compressor to ensure the smooth performance of the compressor and to prolong the life of the compressor. The features discussed above are disclosed in U.S. Pat. No. 4,496,378 to Kish.
A common problem with accumulator-dehydrator assemblies is noise associated with pulsations that result from pressure fluctuations in the system. Pulsations originate in the compressor, run backwards through the system to the canister, enter the canister from the first tube end of the delivery tube, and exit to the evaporator through the inlet. In a vehicle with an air conditioning system, the result is additional noise caused by the pulsations being heard in the passenger compartment. In the prior art, the pulsations have several pathways in which to exit through the inlet of the canister into the evaporator and create noise. The disadvantage of the prior art, therefore, is the inability to significantly reduce the movement of these pulsations through the air conditioning system.
The present invention is an accumulator-dehydrator assembly for use in an air conditioning system having an evaporator and a compressor. The assembly includes a canister with an upper portion for containing vaporized refrigerant and a lower portion for containing liquid refrigerant. An inlet is mounted to the canister to transfer refrigerant from the evaporator to the canister and an outlet is mounted to the canister to transfer vaporized refrigerant to the compressor from the canister. The assembly incorporates a delivery tube, also known as a J-tube or U-tube, with a first tube end positioned in the upper portion of the canister to receive the vaporized refrigerant and a second tube end is connected to the outlet to deliver the vaporized refrigerant to the compressor. A baffle is disposed within the canister. The baffle has a first end connected to the canister and a second end positioned to define a partition between the first tube end of the delivery tube and the inlet. In one object of the invention, the baffle is further defined by being extended across the inlet and substantially surrounding the inlet. In another object of the invention, the baffle is extended into the lower portion of the canister and partially submerged by the liquid refrigerant.
The advantage of the present invention over the prior art is the ability to considerably reduce the pulsations typically associated with pressure systems. The present invention forces the pulsations into the liquid refrigerant prior to exiting through the inlet into the evaporator. This significantly reduces the pulsations entering the evaporator and thus, reduces the noise.